I just did a 1996 single level ranch style home. Roof slope is about 5:12 (lots of attic air volume), housewrap looked like kraft paper, plywood sheathing, good ventilation, etc. Home sat on a fairly level lot with decent grading. The crawlspace soils were well covered with 6mil black plastic and the crawlspace was dry. Along the perimeter of the attic there is mold/ mildew growth that is black/ gray in color... not too thick. The growth starts at the insulation line and extends up a few feet. There is an eave vent every 3rd truss bay with no growth in those bays. There are water droplet stains on the vinyl windows at the head areas of the tracks along the E. end of the home (kitchen, bedroom areas). Seeing as how this is a single level ranch home with good eave overhangs, I see no way that flashing would matter at the windows as they are not exposed to the elements== I am ruling out improper flashing as a potential cause of the moisture stains. I am pretty much stumped as to why there is mold growth in the attic with the water stains on some of the windows. By the way-- the worst mold staining is on the E. end of the attic above the windows with the stains. Anyone have any ideas? This one has me stumped. Oh yeah-- the vapor barrier is installed so the top edge of the barrier is secured to the sill plate at the top of the foundation stem wall-- this is a pretty typical installation for newer homes in this area. I was thinking that maybe condensation from the ground is migrating up to the vapor barrier, and moisture is entering the wall cavity where it condenses on the attic sheathing. Possible? This building science stuff gives me a headache.